[Germ.]—A minute unicellular organism, either animal or vegetable; a micro-organism; a microbe.

Germicide.—An agent having the power to kill germs.

H

Host.—An animal or plant in or upon which another organism lives.

I

Immune.—Not susceptible to a particular disease; also, a person who is not susceptible to a particular disease.

[Immunity.]—The state in which an individual is not susceptible to a particular disease.

Immunize.—To render immune.

Incubation.—The interval between exposure to an infectious disease and the first appearance of symptoms.